Polymers containing hexachlorocyclo-pentadiene and process of making same



POLYMERS CONTAINING HEXACHLOROCYCLO- PENTADIENE AND PRGCESS OF MAKINGSAME Paul Robitschelr, Wilson, and Claude Thomas Bean, Niagara Falls, N.Y., assignors to Hooker Chemical Corporation, Niagara Falls, N. Y., acorporation of New York No Drawing. Application August 9, 1956 SerialNo. 603,175

19 Claims. (Cl. 26045.4)

This invention relates to a new process which comprises reacting ahexahalocyclopentadiene with high molecular weight or polymericmaterials containing aliphatic carbon-to-carbon unsaturation and to theproducts resulting therefrom.

This application is a continuation-in-part of our copending applicationSerial Number 308,921, filed September 10, 1952, issued January 29,1957, Patent No. 2,779,701.

The production of infusible, insoluble polyester resins which are flameretardant and have high resistance to heat is of considerable commercialimportance. For instance, castings, moldings, foamed articles orlaminated structures bonded by polyester type resins are for many usesrequired, or at least desired, to be resistant to fire, and are alsorequired to endure heat without deterioration. Typical illustrations ofapplications having such requirements is bad in castings for liveelectrical contacts which must not be ignited by sparks or bedeteriorated by heat generated therein. Structural members, such aspipes, wall-coverings, panels, ash trays, etc., are furtherillustrations where flame retardance is desirable.

l-leretofore certain chemical adducts have been disclosed as beinguseful in the preparation of ester resins. For example, it is known thatthe maleic acid-cyclopentadiene Diels-Alder adduct resulting fromthediene synthesis and its reaction products with alpha, beta-unsaturateddicarboxylic acids or anhydrides and glycols form resinous compositionswhich may be made insoluble and infusible by further reaction withcopolymerizable olefins to form a cross-linked polymer. Suchcompositions are chemically different from the products of thisinvention because the double bond remaining in the linear unsaturatedpolyester so produced is highly reactive and can enter directly into thecross-linking reaction, whereas, the corresponding linkage in thehalogen-containing derivatives employed in making the compositions ofthis invention is non-reactive in said copolymerization reaction;moreover, they do not possess flame retardance. Attempts have been madeto impart flame retardance to such hydrocarbon type resinous polyestercompositions by in oorporating therein inert fire-proofing agents suchas antimony oxide or chlorinated parafifin wax as fillers which do notenter into chemical reaction with the components of the resin; however,this results in a loss in the desirable properties, particularly withrespect to heat resistance, which are usually associated with polyesterresins, and the property to produce satisfactory articles of commercemay be seriously impaired. Other attempts to impart flame retardance arealso known which involve chemically combining tetrachlorophthali-c acidor anhydride in the polyester resin. Compositions so produced arechemically unrelated to the products of this invention; in addition theyhave only poor flame retardant properties and they usually possess lowstability and low strength at elevated temperatures and are, therefore,not entirely satisfactory for many applications. Still other attemptsinvolving the use of certain unsaturated organic phosphorus compoundsStates Patent C) ICC as cross-linking agents which impart flameretardauce to the final polyester resin have likewise been foundunsatisfactory.

It is an object of this invention to provide resinous compositions whichare highly resistant to burning and yet possess many of the desirablecharacteristics usually associated with polyester resins. provideresinous compositions which are highly resistant to exposure at elevatedtemperatures. A still further object is to prepare resinous compositionswhich are suitable for casting, molding, foaming or laminating and whichare characterized by possessing the desirable properties usuallyrequired in resins in the preparation of castings, moldings, foamedarticles and laminates, and which are also characterized by beingcapable of forming articles of commerce which have a pleasing appearanceand wide utility. A particular object of this invention is to makeavailable in commerce compositions comprising a mixture of anunsaturated polyester and an olefinic crosslinking agent, with orwithout the presence of catalysts and/ or inhibitors and/ or chainterminating agents and/ or promoters or accelerators, which are capableof polymerization to an insoluble, infusible, fire resistant polyesterresin. A further objective is to provide methods for chemicallycombining heXahalo-cyclopentadienes in the form of an adduct into thepolyesters. A still further objective is to provide methods for thepreparation of these unsaturated polyesters and their combination witholefinic cross-linking agents. A further object is to provide a methodfor the introduction of a hexahalocyclopentadiene directly into aprecondensed linear polyester which is the reaction product of apolycarboxylic compound and a polyhydric alcohol without the necessityfor first forming an adduct of the hexahalocycl-opentadiene with one of.the components of the linear polyester or with the cross-linkingcompound. It is a further object to provide a method for theintroduction of the hexahalo cyclopentadiene directly into a polymercontaining olefinic unsaturation. It is still a further object toprovide a method for the introduction of heXahal-ocyclopentadienedirectly into a high molecular weight material containing olefinicunsaturation, such as unsaturated oils, etc. These objects, and otherswill become apparent to those skilled in the art upon consideration ofthe specification and ap-' pended claims.

We have now found that a hexahalocyclopentadiene such ashexachlorocyclopentadiene, hexabromocyclcpentadiene and mixedhexahalocyclopentadienes such as those containing chlorine and bromine,chlorine and fluorine, bromine and fluorine, etc., may be reacted withhigh molecular weight or polymeric materials containing aliphaticcarbon-to-carbon unsaturation, such as ethylenic linkages whetherconjugated or unconjugated, at temperatures below the degradationtemperatures of the reactants and products produced, to yieldhalogen-containing high molecular weight materials or halogen-containingpolymers.

The compositions of this invention can be prepared by the followingmethod. First, a polycarboxylic acid is esterified with a po-lyhydricalcohol, at least one of which contains aliphatic carbon-to-carbonunsaturation. ,Then the hexahalocyclopentadiene is added and the mixturereacted together. The hexahalocyclopentadiene will undergo aDiels-A'lder reaction with the reactive double bonds of the linearpolyester to form an adduct thereof. The type of product formed can becontrolled by varying the degree to which the reaction is carried out.For instance, if the reaction is stopped before all of the reactabledouble bonds of the linear polyester have been reacted upon by amolecule of the hexahalocyclopentadiene, the remaining unsaturation canbeutilized for cross-linking the linear polyester. If the reaction iscarried out until all of the double bonds of the linear polyester havereacted, the

A further object is to reaction product formed will be a thermoplasticlinear polyester which cannot be further reacted.

Esterification of the desired ingredients may be effected in thepresence of esterification catalyst and/or chain terminating agents,etc. A preferred procedure involves introducing the selected ingredientsto be esterified, in predetermined proportions, into a suitableesterification vessel provided with heating and/or cooling means, anagitator, means for maintaining an atmosphere of an inert gas such asnitrogen or carbon dioxide over the reaction mixture, means for removingwater of esterification, an inlet, an outlet, and any other accessoriesnecessary for the reaction. The charged rc;ctants are blanketed with aninert atmosphere, then agitated and heated to effect the reaction forthe specified period of time. After the desired degree of reaction hasbeen attained, as conveniently determined by employing the acid numbertechnique or measuring the amount of water liberated, the reactionmixture is cooled. The resulting product is then chemically reacted withthe hexahalocyclopentadiene only to a degree where some of the reactivedouble bonds of the linear polyester remain unreacted upon. The olefiniccross-linking agent is then added and, together with a polymerizationcatalyst, may be copolymerized with the mixture.

The high molecular weight materials or halogcncontaining polymersobtained in accordance with this invention are characterized by heat andfire resisting properties, as well as chemical resistance. Suchproperties are of considerable value in industrial art for such uses asplastics, protective coatings, etc.

The reaction of hexahalocyclopentadiene with a high molecular weight orpolymeric material containing aliphatic carbon-tocarbon unsaturationproceeds with the formation of a diene addition product of thehexahalocyclopentadicne with the unsaturated high molecular weightcompound. The addition products are heat stable up to temperaturesaround 200 degrees centigrade or even higher and yet they readilydecompose with the liberation of gaseous products at flame temperaturesand exhibit fire resistant properties. Hence, such products show a verydesirable property of thermal stability combined with fire resistance.

The location of the aliphatic carbon-to-carbon unsaturation in the highmolecular weight material determines the place at which the reactionwith the hexahalocyclopentadiene proceeds. By selection of highmolecular weight materials wherein the unsaturation is located indifferent parts of the molecule, it is possible to obtain a variety ofproducts. It is, for instance, possible to make high molecular weightmaterials, such as shown in examples below, to contain a specific numberof double bonds separated by specific segments. By such means, highmolecular weight materials are obtained which have controlled amounts offire resistance, chemical resistance or other properties.

The reaction between the hexahalocyclopentadiene and the materialcontaining carbon-tocarbon unsaturation can be brought to differentdegrees of completion. By doing so, the extent of both the halogencontained in the product as well as the residual aliphaticcarbon-to-carbon unsaturation may be controlled. Where the residualaliphatic carbon-to-carbon unsaturated bonds still exhibit activity forpolymerization reactions, even higher molecular weight compounds orcross-linked polymers can be obtained by the addition of a polymerizingmonomer such as styrene, vinyl esters, acrylate esters, vinyl chloride,etc.

Among the high molecular weight or polymeric mate rials containingaliphatic carbon-to-carbon unsaturation, we include such naturallyoccurring materials as unsaturated vegetable or animal oils such aslinseed, soya, tung, sesame, sun fiower, cottonseed, herring, menhaden,and sardine oils. etc., or chemically modified naturally occurringmaterials such as allyl ethers of starch, cellulose, or acrylate estersthereof, etc., synthetic drying oils, polymers obtained bypolyesterification of such unsaturated compounds such as maleic,fumaric, itaconic, aconitic, chloromaleic, dimerized fatty acids,anhydrides or acids or from allyl glycerol ether, methallylglyccrolether, glycerol monoacrylate, butenediol, pentencdiol, or polymersobtained by polyethcrification of the unsaturated polyols.

in carrying out the reactions embodied in this invention we commonlyemploy temperatures in excess of about degrees centigrade, althoughtemperatures below 80 degrces centigrade can be employed if the reactiontimes are extended. The reaction proceeds smoothly, the exotherms duringreaction being in most cases only minor. The reaction is best carriedout in the liquid phase, where in the hexahalocyclopentadiene may act asa solvent for the high molecular weight aliphatic carbon-to-carbonunsaturated compound. Alternatively, an inert solvent such as benzene,chlorobcnzcne, or dibutyl ether can be employed. It has been found thatit: the amount of solvent is insufficient, there is a greater likelihoodof forming cross-linked high molecular weight compounds than if theamount of solvent or excess hcxahalocyclopentadiene is large. Uponreaching a desired extent of reaction, the excesshexahalocyclopentadiene or inert solvent can be removed by such means asdistillation with or without steam, solvent stripping or other commonlyltnown means. As is common with other chemical reactions, adequateagitation is desirable for improving the reaction rates.

If the carbon-to-carbon unsaturation ot"; the high molecular weightmaterial is susceptible to polymerization reactions, it is usuallydesirable to carry out the reaction with the hexahalocyclopentadiene inthe presence of a small amount of a polymerization inhibitor such ashydroquinone, picric acid, phenylcne diamine. This inhibitor may beretained or removed for further polymerization with monomers as desired.The polymerization of the hexahalocyclopentadiene-containing productswith monomers is catalyzed by the conventional peroxidic catalysts, suchas benzoyl peroxide, etc., or by ultraviolet light, heat, etc.

The maximum amount of hexahalocyclopentadicne which can be combined withthe starting high molecular weight material is primarily determined bythe latters aliphatic carbon-to-carbon unsaturation content. However,the reaction can be stopped at any stage prior to completion of thereaction.

The utility of materials resulting from practicing this invention isfurther illustrated in the examples below.

The following examples are given to illustrate our invention. However,they are not to be construed as limiting the invention except as definedin the appended claims.

Example 1 Equimolar proportions of ethylene glycol and maleic anhydridewere reacted at a temperature up to 220 degrees centigrade until apolymer having an acid number of approximately l25 was attained. Thereaction mixture was cooled to about 130 degrees centigrade. One-halfmole hexachlorocyclopentadiene per mole of maleic anhydride and 0.16mole of hydroquinone per mole of maleic anhydride originally esterifiedwere then blended into the reaction mixture. The reaction was continuedat a temperature of 130 degrees centigrade for about eight hours, at theend of which time a fusible, acetone-and-bcnzenesoluble polyester resinwas recovered having hexachlorocyclopentadiene chemically combined intothe polyester chain, and also containing at least 50 percent of theoriginal number of olefinic linkages still capable of entering into thecross-linking reaction. This was confirmed by mixing about parts of theproduct with 30 parts of styrene to form a solution, and polymerizingthe resinous solution by the addition of 1.3 parts of benzoyl peroxideas a polymerization catalyst, and by subsequently heating to atemperature of about 50 degrees centigrade. An infusible, insoluble,hard, tough, amber-colored asses-4e material was obtained which wasself-extinguishing on removal from an oxidizing flame.

The solution of the halogen-containing polymer and styrene producedabove can be cast into a variety of molds and cured to form thermosetcastings which are useful for a wide variety of applications. Asexamples, electrical components can be potted; plate material can becast which has many desirable optical properties; or castings can beproduced and subsequently machined into buttons, door-knobs, handles,etc. The solution can be used to impregnate glass fibers, in the form ofmats, cloths, or strands; and upon curing, extremely high strengthreinforced plastic materials are obtained which are suitable as buildingpartitions, skylights, electrical cord, motor-car bodies, containers andfor many other uses. If suitable foaming agents are added, cellularproducts are obtained which are strong, lightweight, and fire resistant.

Example 2 Ninety grams of linseed oil were placed in a reaction flaskequipped with means for temperature control and temperature recording.To this were added 27.3 grams (0.1 mole) of hexachlorocyclopentadiene.The mixture contained in the flask was heated in an oil bath and thetemperature of the reaction mixture was maintained at about 165 degreescentigrade for a period of two hours, after which time the reactionflask was removed from the hot oil bath and allowed to cool to roomtemperature.

The contents of the reaction flask was then subjected to a vacuum of 50millimeters of mercury and heated to 135 degrees centigrade to 143degrees centigrade. No distillate was obtained. The resulting producthad no odor of hexachlorocyclopentadiene. The product so recovered wasanalyzed and found to be an addition product ofhexachlorocyclopentadiene with linseed oil containing a chlorine contentof 18.0 percent (theory 18.15), and an iodine value of 122 (theory 123).The product is useful for the preparation of chlorine-containingmodified alkyds.

Such modified alkyds can be prepared by reacting the products of Example4 with various polybasic acids or anhydrides such as phthalic or maleicanhydrides and with additional polyols such as glycerol,pentaaerythritol, etc. The resultant modified alkyd shows improvedhardness, Water resistance as well as fire resistant properties. It isuseful in the preparation of water resistant, fire resistive lacquers,enamels and paints.

The addition product of hexachlorocyclopentadiene and linseed oil canalso be used directly as an ingredient in oil modified alkyds or asplasticizer or extender of polymeric materials in order to improve suchproperties as water and fire resistance.

Example 3 To 2374.4 grams of allyl glycerol ether in a threeneckedround-bottom flask was added 2625.6 grams of adipic acid. The flask wasfitted with a stirrer, nitrogen bubbling tube, thermometer anddistilling head. The flask was then lowered into an oil bath and heatedat 161 to 166 degrees Centigrade with stirring and passage of nitrogenwhile reaction was taking place. When an acid number of 72 had beenreached the reaction mix was removed from the flask and poured intotrays.

The product was a light amber colored polyester resinous in nature andcompletely thermoplastic.

Example 4 To 15.0 grams of the allyl glycerol ether adipate resin fromExample 3 was added 2.6 grams of hexachlorocyclopentadiene and 0.088gram (0.5%) of hydroquinone. The mixture Was placed in a one-inch bysix-inch test tube and heated at 125430 degrees centigrade under a veryslow stream of nitrogen for 64 hours. The product was an amber liquidcontaining 11.5 percent of chlorine.

6 It wasdissolved in 10 grams of styrene. was catalyzed by 0.2 gram ofLuperco ATC (50% paste of benzoyl peroxide in tricresyl phosphate). Thesolution was heated at degrees centigrade and cured to a tough thermosetproduct which was fire retardant. The uses of the product are similar tothose of Example 1.

From a consideration of the foregoing examples it is apparent thatvarious modifications may be made falling within the scope of thisinvention without departing from the spirit and intent thereof. Forinstance, although we have chosen to exemplify our invention in detailby using hexachlorocyclopentadiene, other hexahalocyclopentadienes, andmixed hexahalocyclopentadienes may be substituted therefore withoutadversely affecting the properties thereof.

We claim:

1. The process which comprises reacting hexahalocyclopentadiene whereinthe halogen is selected from the group consisting of chlorine, bromine,fluorine and mixtures thereof with a material selected from the groupconsisting of (1) aliphatic unsaturated linear polyesters of apolyhydric alcohol and a polycarboxylic compound selected from the groupconsisting of polycarboxylic acids and polycarboxylic anhydrides, and(2) glyceride drying oils.

2. The process of claim 1 wherein the hexahalocyclopentadiene ishexachlorocyclopentadiene.

3. The process of claim 1 wherein the material is a drying oil.

4. The process of claim 3 wherein the drying oil is linseed oil.

5. The process of claim 3 wherein the drying oil is soya bean oil.

6. The process of claim 1 wherein the material is an unsaturated linearpolyester resin.

7. The process of claim 6 wherein the ratio of hexahalocyclopentadiencto unsaturated linear polyester resin is less than the theoreticalrequired to react with all of the unsaturation in said polyester.

8. The process which comprises reacting hexachlorocyclopentadiene withless than the total number of unsaturated aliphatic carbon-to-carbonlinkages contained in an aliphatic unsaturated linear polyester of apolyhydric alcohol and a polycarboxylic compound selected from the groupconsisting of polycarboxylic acids and polycarboxylic anhydrides toproduce an unsaturated polyester resin containing thehexachlorocyclopentadiene in chemical combination therewith.

9. The process which comprises reacting hexachlorocyclopentadiene withless than the total number of unsaturated aliphatic carbon-to-carbonlinkages contained in an aliphatic unsaturated linear polyester of apolyhydric alcohol and a polycarboxylic compound selected from the groupconsisting of polycarboxylic acids and polycarboxylic anhydrides toproduce a polyester resin containing the hexachlorocyclopentadiene inchemical combination therewith, mixing said product with acopolymerizable compound containing carbon-to-carbon unsaturation, andeffecting the polymerization of the mixture until an insoluble,infusible polyester resin is produced.

10. A composition of matter comprising a polymerizable linear polyesterwhich is the reaction product of (1) a hexahalocyclopentadiene, whereinthe halogen is selected from the group consisting of chlorine, bromine,fluorine and mixtures thereof, and (2) a material selected from thegroupconsisting of (1) aliphatic unsaturated linear polyesters of apolyhydric alcohol and a polycarboxylic compound selected from the groupconsisting of polycarboxylic acids and polycarboxylic anhydrides, and(2) glyceride drying oils.

11. A composition of matter comprising a polymerizable linear polyesterwhich is the reaction product of (1) a hexahalocyclopentadiene whereinthe halogen is selected This mixture from the group consisting ofchlorine, bromine, fluorine and mixtures thereof, and (2) an aliphaticunsaturated linear polyester of a polyhydrie alcohol and apolycarboxylic compound selected from the group consisting ofpolycarboxylic acids and polycarboxylic anhydrides.

12. A composition of claim ll wherein said hexahalocyclopentadiene (l)is hexachlorocyclopentadicne.

13. A polymerizable mixture comprising the composition of claim 12 inadmixture with (B) a polymerizable compound containing aliphaticcarhon-to-caroon unsaturation.

14. A composition of claim 13 wherein said polycarboxylic compound ismaleic acid.

15. A composition of claim 13 wherein said polycarboxylic compound ismaleic anhydride.

16. A composition of claim 13 wherein said polyhydric alcohol is aglycol, said polycarboxylic compound is maleic acid, and saidpolymerizable compound (13) is styrene.

17. A composition of matter comprising the reaction product ofhexachlorocyclopentadiene with glyceride a drying oil.

18. A composition of matter comprising the reaction product ofhexachlorocyclopentadiene with linseed oil.

19. A process for the production of a polymerizable mixture whichcomprises (1) reacting a polyhydrie nlcohol with a polycarboxyliccompound containing aliphatic carbon-to-carhon unsaturation selectedfrom the group consisting of polycarboxylic acids and polycarboxylicanhydrides, (2) reacting the condensation product thus formed with ahexahalocyclopentadienc at an elevated temperature, (3) and adding apolymerizable compound containing aliphatic carbon-to-carhouunsaturation to the reaction product formed in step (2).

References Qited in the file of this patent UNITED STATES PATENTS2,404,836 Gerhart et al -2 July 30, 1946 2,475,664 Gerhart et a1 July12, 1949 2,598,424 Peters May 27, 1952 2,606,910 Herzfeld et a1 .d Aug.12, 1952 2,779,701 Rohitschek et a1. Jan. 29, 1957 UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 2 ,863 ,848 December 9, 1958Paul Robitschek et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 7, line 21, for Yglyceride a" read a glyceride Signed and sealedthis 10th day of August 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner ofPatents

1. THE PROCESS WHICH COMPRISES REACTING HEXAHALOCYCLOPENTADIENE WHEREINTHE HALOGEN IS SELECTED FROM THE GROUP CONSISTING OF CHLORINE, BROMINE,FLUORINE AND MIXTURES THEREOF WITH A MATERIAL SELECTED FROM THE GROUPCONSISTING OF (1) ALIPHATIC UNSATURATED LINEAR POLYESTERS OF APOLYHYDRIC ALCOHOL AND A POLYCARBOXYLIC COMPOUND SELECTED FROM THE GROUPCONSISTING OF POLYCARBOXYLIC ACIDS AND POLYCARBOXYLIC ANHYDRIDES, AND(2) GLYCERIDE DRYING OILS.